Electric switch



April 9, 1929. PFElFER 1,708,431

ELECTRIC SWITCH Filed June '7, 1926 2 Sheets-Sheet l umrzvrozz.

- l BY. l'u

ATTORNEYJ.

April 9, 1929. .1. PFEIFER 1,708,431

ELECTRIC SWITCH Filed June 7, 1926 2 Sheets-Sheet 2 Z2 4 Z8 Z] 3 LIE. 1 11 Z1 4 Z9 IHHHHIH ATTORNEYS.

.; trash UhllTEQ STATES PATENT'GFHQE.

JOHN PFEIFER, G1 SPRZNGFIELD, OHIO, ASSIGNOR OHE-THIED TO SPENCER W.

- VIARING, OF SPRINGFIELD, OHIO.

'nLno'rRrc SWITCH,

Application filed June 7, 1926. Serial No. 114,043.

My invention relates to improvements in electric switches, it more particularly relating; to a switch which is thermostatically controlled.

The object of my invention is to provide simple and effective devices for opening and closing electric switches b mechanism which controlled by thermostat.

A further object of the invent on is to Jl'OVltlG a switch operati mechanism of the character described which can be adusted to a niccty so that the mechanism will be responsive to but slightehanges m temper-attire if desired; the adjustment being such, however, that the mechanism can be regulated to operate upon wider ranges of temperature. 7 y

In the accompanying drawings:

F l is a top plan view of a mechanism embodying the improvements.

2 is a side elevation of the same showing the switch in closed position.

Fig. 8 is a section on the line 33 of Fig. l. v

Fig. l is a side elevation showing the n open position.

is a section on the line 5 of to the drawings, 1 represen s a suppo t base for the mechanism. Mounted on this base is a motor, shown in ""lltease as a spring motor, 2 and 2 ating; upright supports, 3 an arbor suitably mounted in tie supports, d a coil spring having; one end connected to the arbor 3 and the other end tired to a cross-rod 2 connecting the supports 2 and 2, 5 a key for winding the spring, 6 aratchet wheel fixed to the arbor, 7 a gear wheel loose on the arbor, 8 a pawl pivotally connected with the wheel and engaging the teeth of the ratchet wheel, and 9 a spring bearing on the pawl. The gear wheel 7 meshes w th a second gear wheel 10 lined to a short shaft ll which mounted to rotate in the support 2 and another upri 'ht support 12. The gear 10 is in mesh with a pinion l3 fixed'to a shaft ll which has one end journaled in the support 2 and the other end journaled in the upright support 15. Fixed to the shaft 14 is an escapement wheel 16 having a plurality of equally-spaced teeth 17, and a switch operating disk 18 also having a plurality of equally-spaced projections 19 corresponding in number to the teeth 17 Cooperating with the teeth of the escapement wheel 16 are two detents 20 and 2*, arranged on opposite sides of the escapement wheel. The detent 20 is formed on a long arm 22 which projects at right axis of the wheel with a portion thereof lying in close proximity to the wheel, that portion being arched as indicated at 22 to avoid the shaft 14. The detent'2l is adjustably connected to the arm 22 and to that end is formed on a separate plate 23 which has lateral flanges 24 on its upper and lower edges to embrace the arm 22 and also has a slotted opening 25 through which passes a screw 26 secured to the arm 22 so as to slidably connect the same with the arm. The end of the arm 22 is bent to form a laterally projecting ear 2? and the outer end of the plate 23 is bent to form a laterally projecting ear 28 parallel with the ear 2?. These ears have ali ned openings to receive an adjusting screw 29, the opening in the ear 28 being unthreaded and the opening in the ear'27 being threaded. The ear 28 also has a threaded opening to receive an adjusting screw the end of'which bears against the ear 27. By turning the screw 29 the plate 23 and its detent 21 may be slid on the arm 22 in the direction of the escapement wheel while by turning the screw 30 the plate and its dctent are moved in the opposite direction away from the escapcment wheel.

The other end of the arm 22 is pivotally connected to one arm 81 of a bell crank lever pivoted at 32 to a bracket 3% on the base 1. The other arm this bell crah lever is pivotally connected a yoke 3 1, connected to one member of a two-part red, the other member 36 of whic i is con nected to one wall of a thermostat 87 of the.

bellows type, the other wall being supported by the bracket 38. The two members and 36 of the rod and the yoke are adjustably connected together so that the connection can be lengthened or shortened and to this end the member is shown as having a' reduced threaded stem 39 threaded into the member 36, and the yoke has a threaded stem l0 threaded in the member The stems are oppositely threaded so that by turning the member the connection may be lengthened or shortened, which, through the bell crank lever and arm 22, serves to adjust the detent 20 with relation to the teeth 17 of the escapement wheel.

angles to the v The necessary movement oil the arm 22 under the action of the thermostat is permitted by pivotally supporting that end opposite the bell crank lever, and to that end the arm has attached thereto an arm ell by a screw i2, the arm all being pivotally supported by a bracket -;l-3 secured to the base. The screw &2 passes through the slotted opening to permit of the adjustment of the detent carrying plate In operation the mechanism is installed at any suitable point where it is desired to regulate temperature, such for instance as on an incubator for chickens, in which case the heat responsive element would be located in the incubating chamber. As the walls of the bellows contract or expand in response to the temperature, the bell crank lever is rocked and the arm 22 thereby moved in a direction substantially at rightangles to the axis of the escapement \vheel. This movement causes one of the detents to release the escapement wheel and the other detent to be projected in the path of one of the teeth of the escapement wheel to again arrest the wheel. By adjusting the detents in the manner described it is possible to release the escapcment whee by a change in temperature of but a fraction of a degree if it is desired to maintain a substantially even temperature, as is the practice in incubation. lVhen the escapement wheel is released it permits a partial rotation of the "am disk 18 so as to cause the cam projections thereon to either open the switch by contacting the pivoted member of the switch, as shown in Figs. 3 and l, or permit the switch to close. by freeing the pivoted member of the switch as indicated in Fig. 2.

The switch which 1 employ consists ol a stationary contact member l l, supported on the base, and a movable contact member ll) supported on one end of a lever 46, the other end of which stands in the path of m vement oi the tam projections on the dish 18. The lever 46 his cars l7 which are pivotally connected to the ears of a supporting bracket 1-8 connected with the base 1. The arrangement is such that when the escapement wheel is released by the detent 21, one of the cam projections on the dish 18 will strike the lever 46 and separate the contacts l land as shown in Fig. and :l. while when the (SCflpLillQlll wheel released by the dcleut :30 the movement ot the dish 18 is .such that the next succeeding cam tooth will be removed from the end of the lever 46, as shown in Fig. 2, so as to permit the lever to swing by gravity and by the aid of a spring l9, to close the contacts.

Having thus described my invention, I claim:

1. In an electric switch, a switch ope ating member, a motor for operating same, a toothed escapement wheel and two detents for same to release and arrest said motor, and a temperature responsive element for controlling; said detents.

2. In an electric switch, a switch operating member, a motor for operating same, a toothed escapement wheel and two detenis for same to release and arrest said motor, a temperature responsive element "for controlliug said detents, and means :l'or adjusting the deients relatively to the teeth oil said wheel.

3. in an electric switch, a switch operating member, a motor for operatin same, a toothed escaj icmcnt wheel rotated by the motor, a movable support arrang ed adjacentsaid wheel, two deteuts carried by said support and cooperating with the teeth of said escapement wheel to release and arrest said motor, and a temperature resrmnsive element connected with said movable support.

in an electric switch, a switch operating; member, a motor for operating same. a toothed escapemei'it wheel rotated by the motor, a movable support arranged adjacent said wheel, two detents carried by said supports and cooperating with the teeth of said escapcment wheel to release and arrest said motor, a. temperature l'GSptHlSiYi} element connected with said movable support, and means for adjusting said detents relatively to the teeth of said wheel.

5. in an electric switch. a switch operating member, a. motor for operating same, a toothed wheel rotated by said motor, a supporting arm movably mounted adjacentsaid wheel, a detent adjustably carried by said arm, a second dctent fixedly carried by said arm, a temperature responsive element. and an adjustable connection between said element and said arm.

(5. in an e ectric switch, a switrh operating member, a motor 'lor operating}; same, a toothed wheel rotated by said motor, a support movably mounted adiarent said wheel,

a. pair of detents carried by said support and cooperating with the teeth of said wheel. a hell crank lever to one arm oi which said support is connected, and a temperature responsive element connected to the other arm oi said hell cranl; lover.

l in an electric switch, a switch o erah inn member. a motor for operat ng; same. a toothed member movable with the motor.

l a pair oi detonts arranged 'ioisimuleous movement altcrna'tolv into and out of the path oi the teeth of said member. and a temperature responsive element for mo viii 5;; said detents.

in testimony whereof, I have hereunto set my hand this 3rd day of June, 1926.

JOHN Pl lflll l lll. 

